There's a fantastic passage, not by Murr the Cat, but those rising from the random sheets of waste paper that, I think, are the best depiction of practicing I've ever read.

Thankfully, someone has already done the work of quoting the Penguin Classics English translation of the passage here, which I'll paste below. Notably, the quoter appears to be a pianist and their own introduction and conclusion to the passage are also worthy of note.

Aside from the quote is the equally interesting allusion a few paragraphs later to one Stefano Pacini, a luthier which the Penguin "Notes to Part 1" suggest "may have been the maker of Hoffman's own guitar."

Consider from page 41 of the Penguin edition the following passage …

The Princess overcame her alarm, and looked very closely at the instrument, whose strange shape would have shown its great age even had that not been confirmed by the date and the maker's name, which could clearly be seen on the bottom of the body through the hole in the soundbox, for the words 'Stepfano Pacini fec. Venet. 1532' were etched there in black.

Interestingly, while Hoffman lived in the 18th and 19th centuries, the "guitar" in the book is likely not what we now think of as a guitar. The "guitar" in this passage seems anachronistic to me as a 16th century guitar-like instrument was probably a vihuela or something similar in reality. In a fictional novel it can, of course, be whatever it needs to be.

Anyway, here's the original poster's quotation of the Hoffman passage …

My friends, I hope you will indulge me in a longish excerpt from E.T.A. Hoffmann's Lebens-Ansichten des Katers Murr from the Penguin Edition translated as 'The Life and Opinions of the Tomcat Murr'. It is one of the best descriptions of a musician's frustration I have read in a long time..

Quote:

In short, Princess Hedwiga smiled, but as she opened her rosy lips to say something in reply to the gentle unartistic Julia, they heard the sound of chords very close to them: chords played so powerfully, so wildly, that the instrument hardly seemed to be an ordinary guitar.The Princess fell silent, and both she and Julia hurried out of the fisherman's cottage.Now they heard tune after tune, linked by the stranges of transitions, the most outlandish sequences of chords. From time to time a resonant male voice could be heard, now exploring all the sweetness of an Italian song, now suddenly breaking off and falling into grave and gloomy melodies, now singing in recitative style, now speaking firm and forcefully accentuated words to the music.The guitar was tuned – there were more chords – they broke off again; more tuning – vehement words spoken as if in anger – then melodies – and then more tuning again.

Full of curiosity about the strange vituoso, Hedwiga and Julia stole closer and closer, until they caught sight of a man dressed in black with his back turned to them, sitting on a rock close by the lake and playing the guitar in this odd manner, sometimes singing, sometimes speaking.

He had just entirely retuned the guitar in an unusual way and was now trying a few chords, exclaming from time to time: 'Wrong again – no purity – now a trifle of a semitone to low, now a trifle of a semitone too high!'

Then, having slipped the instrument free of the blue ribbon from which it hung around his shoulders, he took it in both hands, held it in front of him, and began: 'Tell me, you wilful little creature, where's your melody, in what corner of your being has the pure scale hiden? Or do you mean to rebel against your master and say his ear has been hammered to death in the smithy of equal temperament, and his enharmonics are just a childish picture puzzle? I believe you are mocking me, even though I wear my beard much better trimmed than Master Stefano Pacini, detto il Venetiano, who laid within you that gift of melody which remains an impenetrable mystery to me. Now let me tell you, dear creature, if you are determined not to allow the concordant dualism of Gs and As or Cs and Ds – or rather, of all the notes – then I will set nine good German masters loose on you, to take you to task and get the better of you with enharmonic remarks. And there'll be no flinging yourself into the arms of your Stefano Pacini, there'll be no insisting on having the last word like a shrewish woman. Or are you pround and arrogant enough to think that all the pretty spirits dwelling in you will obey only the mighty magic of enchanters who left this earth long ago, while in the hands of a fool – '

At this last remank the man suddenly stopped, jumped up, and gazed out at the lake like one lost in deep thought. The girls, intrigued by his strange actions, stood behind the bushes as if rooted to the ground; they scarcely dared to breathe.

'The guitar,' burst out the man at last, 'is surely the most miserable and imperfect of all instruments, worthy only to be taken up by lovesick, mooning shepherds who've lost the mouthpieces of their shawms, for otherwise they'd blow a hearty tune, arousing echoes with cowherd's melodies of the sweetest desire, and sending mournful music in the direction of their Emmelines in the far mountains, rounding up their pretty cattle with the merry crack of supple whips! Oh God! Shepherds who sigh "like a furnace to their mistress' eyebrow" – teach them that the triad is just three notes, and may be knocked down when stabbed by a seventh, and put the guitar into their hands! And as for grave fellows with a toleable amount of education, men of great erudition who occupy their minds with the wisdom of Greece and know what happens at the court of Peking or Nanking, but understand not the least thing about sheep and sheep-breeding, what's such whining and strumming to them? What are you about, you fool? Remember the late Hippel, who tells us that the sight of a man teaching the piano makes him feel as if that teacher were boiling eggs – and now strumming the guitar – shame on you, you fool!'

With which the man flung the instrument away into the bushes, and strode quickly off without noticing the girls.

Were the piano only light enough to lift, many are the times I would have cried thus and flung the thing out the window…